Can someone help with IDing a handgun?

My first post and I hope some of you knowledgable folks can help me out.

My wife is out of town settling a relative's estate and has stumbled upon a unique (to me) handgun. I have googled my brains out and have come up with nothing. I have only viewed it on her webcam and this is the best description I can come up with

It's about a foot long, single shot, with an in-line external hammer with TWO TRIGGERS within a trigger guard. I believe it breaks open like a shotgun to load as there appears to be a pin protruding vertically in front of the trigger guard. I cannot discern the caliber as she refuses to point it at her webcam. It has no markings other than a four digit number on the butt. It has wooden grips and the side plates are not a smooth blue steel. The sideplates look like a dull mottled coloring sort of what Ruger used on some of it's revolvers.

My wife is afraid to handle it insofar as trying open the action or ascertain the function of the triggers.

Knowing the previous owner (94 years old) I think the weapon may date to somewhere around WWII. He was not a gun collector, but was in that war in Europe. She has also found a Colt 45 with foreign language markings.

It's a target pistol, probably from the period 1875 through 1920, or thereabouts.
It is based upon a small Remington "rolling block" action, maybe originally for a rifle, maybe originally for a pistol (they made both).
It has double-set triggers.

How to make sure that it's safe:
Point the pistol in a safe direction. Do not touch the hammer, which appears to be down ("fired").
Pull the rear trigger until it "clicks" into place. If it doesn't "click," then it's already set, so stop. Pull the front trigger, which should go off almost just because you're looking at it (light trigger pull).
Now it's safe to cock the hammer by pulling it all the way back until it, too, "clicks" into the cocked position and stays there.
Next, flip the rotating breech-block back and down, using the "ear" that protrudes from it. When the breech-block is open, the gun won't fire, no matter what you do.
Look into the breech. It should be empty, so you can see all the way out the muzzle end of the barrel. If it isn't, there's something stuck in its bore, so take it to a gunsmith. If there's a cartridge in it, remove it yourself.
Once the barrel is completely empty, you can "ear" the breech-block closed. To safely drop the hammer, thumb it back past cocked a little, pull the front trigger and hold it all the way back, and carefully lower the hammer all the way down.

Now that you know it's empty, you can handle it and try to discover its caliber, and whether it's a center- or rim-fire (they made both).
It appears to have modern sights. It may have been made in modern times from an old action, instead of having been made when the action was new.
Maybe remove the fore-end, and look for markings.

A real Remington action is quite strong, and can be used with modern cartridges if the barrel is sound and properly made. Ask a gunsmith for advice, if it uses anything more powerful than .22 Long Rifle.
After making sure that the triggers are not set (see "making it safe," above), cock the hammer, open the breech, insert a cartridge, close the breech, assume your shooting position (pointing the gun downrange), and cock the rear trigger by pulling it back past the "click." Sight carefully, and then just touch the front trigger. Bang!
Repeat.